Preliminary Information
The crystal specification is as follows:
MT8843
Applications
The circuit shown in Figure 9 illustrates the use of the
MT8843 (CNIC2) device in a typical CID or CLIP sys-
tem. Network protection will differ depending on the
market for which the product is designed.
Notes:
CNIC2 has not been fully characterized for talkoff
and talkdown performance as specified in SR-TSV-
002476.
For CIDCW, speech immunity improves if near end
audio is cancelled from the incoming signal. One
possible implementation is to connect the signal
input to the 2 wire side when the CPE is on-hook and
the 4 wire side when the CPE is off-hook.
Frequency:
Frequency tolerance:
Resonance mode
:
Load capacitance:
Maximum series resistance
:
Maximum drive level (mW):
e.g., CTS MP036S
3.579545 MHz
±0.1%(-40°C+85°C)
Parallel
18 pF
150 ohms
2 mW
Any number of MT8843 devices can be connected
as shown in Figure 8 such that only one crystal is
required. The connection between OSC2 and OSC1
can be D.C. coupled as shown, or the OSC1 inputs
on all devices can be driven from a CMOS buffer (dc
coupled) with the OSC2 outputs left unconnected.
VRef and CAP Inputs
V
Ref
is the output of a low impedance voltage source
equal to V
DD/2
and is used to bias the input op-amp.
A 0.1µF capacitor is required between CAP and V
SS
to suppress noise on V
Ref.
+5V
TIP / A
For BT network
protection:
TISP4180,
TISP5180,
TPA150A12 or
TPB150B12
+5V
34K
MT8843
CNIC2
IN+
0.1µF
V
DD
St/GT
ESt
StD
INT
CD
DR
DATA
DCLK
FSKen
PWDN
IC
420K
420K
430K
0.01µF
+5V
Notes
RING / B
53K6
430K
0.01µF
34K
+5V
60K4
464K
IN-
GS
V
Ref
CAP
+5V
100K
500K
0.1µF
500K
R
0.33µF
TRIGin
TRIGRC
TRIGout
MODE
0.1µF
OSCin
OSCout
V
SS
500K
0.1µF
200K
C
300K
= To microcontroller
Note: For CTA applications where there is a requirement to determine
the ring burst duration, the value of R and C may have to be optimized.
= From microcontroller
(FSK Interface Mode 0 selected)
Figure 9 - Application Circuit
5-29
0.1µF
MITEL [ MITEL NETWORKS CORPORATION ]
